Open Source at 90 MPH

The computer operating system Linux and the Web browser Firefox are generally considered the two biggest successes of the movement to develop open-source programs—software anyone can modify, transform, and redistribute back into the community. While there are thousands of other examples, Linux and Firefox have managed to mount serious competition to established commercial products, and have therefore come to represent this specific, collective mode of creation.

But Linux and Firefox are made of bits. They are immaterial. Bits can be shared and sent around easily, so that distant people can work on them concurrently; bugs can be corrected almost instantly; new versions containing updates, improvements, or fixes can be released virtually for free.

So here's a question: Can open-source practices and approaches be applied to make hardware, to create tangible and physical objects, including complex ones? Say, to build a car?